To connect to Amazon RDS PostgreSQL DB we need a client software. In this case we use pgAdmin.
After it is successfully installed we follow the steps below to connect it to the Amazon RDS.
From the DB instance details get the end point.
As it is a browser based interface, choose the add server option as shown in the below diagram.
Use the end point and the master user credentials as the connection details.
Once connected, we get the following window.